Dinan Cars designs and manufactures aftermarket performance parts for BMW and MINI automobiles. The company was founded in 1979 by Steve Dinan and is headquartered in Morgan Hill, California.

Its parts are marketed through a network of authorized BMW dealers and independent auto repair shops. The company has a long-standing arrangement with the BMW dealers, allowing Dinan-modified vehicles to retain factory warranty coverage and even qualify for BMW's Certified Pre-Owned program -- something often lost when vehicles receive aftermarket modifications.

Dinan’s comprehensive warranty program, introduced in 1996 with the cooperation of BMW of North America, provides BMW owners with matching coverage to that offered by BMW’s new car warranty, ensuring that Dinan performance enhancements and the BMW they have been installed in covered for up to 4 years or 50,000 miles.

There are 180 locations in the United States that sell Dinan parts or cars; 150 of them are BMW dealerships. One of Dinan’s goals is to help and support these dealerships in hopes to increase sales from 5,000 cars a year to 15,000 cars a year.[1]

Dinan Cars makes some of the most highly research and developed aftermarket modifications for various models of BMW and MINI’s, some of which include Steve Dinan’s personal 2000 E39 M5, which has what the company calls an “S-2” package.[1][2][3] The S-2 Package modifies the OEM Air filtration system, air mass flow meters, independent throttle bodies, remapped ECU (Electronic Control Unit), exhaust headers, header-back exhaust system, VANOS MAPS, dual mass flywheel, differential, strut brace, and new wheels and tires. The OEM air filters are re-routed to down behind the front air ducts with Dinan’s carbon fiber piping because of the proximity to the engine.[2] Dinan and his team found that at 90 mph, the big V8 was starved of air, so the use of the new air intake system eliminates that effect.[3] Each of the 8 individual throttle bodies were replaced with shorter, greater diameter bodies to withstand the higher RPM’s the engine was going to take on.[1][2] With the extra amount of air, the double VANOS is remapped through the electronic control unit. The factory headers are replaced with more free flowing ceramic-coated stainless steel headers, which give the E39’s V8 28 more bhp than stock alone.[3] To replace the rest of the heavy factory exhaust, Dinan connects the ceramic-coated headers with a more free flowing true dual exhaust.[3] To take full advantage of the newly freed up power, Dinan changes the differential with a shorter ratio 3:45:1 limited slip.[2][3] The final additions are an alloy strut brace and Dinan’s signature 18-inch forged wheels with Michelin’s Pilot Sport 2’s.[2][3] Weighing in at a hefty 3965 pounds, the E39 M5 drives like a true supercar with Dinan’s S-2 package. The full leather and wood interior make the super sport sedan seem more like a limousine than a sports sedan. Dinan says, “You can drive this car at a steady 150 mph while drinking a cup of coffee.”[2]

Applications

Dinan Cars not only produces some of the most highly researched and developed BMW and MINI’s, Dinan also makes some of the most smooth and crisp high horsepower ones.[1][3] The top model, BMW M3 SR-3, is worth almost double ($100,000) what can be purchased for at a dealer, and, according to Auto Week, the car has every right to be so pricey.[1] Dinan’s S3-R M3 is just what BMW designed the car to be, but better in performance and handling without the uptight feel of a traditional race car.[1] The attributes that make the S3-R M3 so special are the Vortech gear-driven supercharger, air-to-air intercooler, bigger fuel injectors, better oil cooler and radiator, and a new engine tuned to perfect all of the newly added horsepower.[1] This setup gives the S3-R M3 a total of 462 hp and 328 lb-ft of torque at the flywheel.[1] To put all of the horsepower to the pavement, Dinan adds a 3.91 Limited slip differential, Dinan/JRZ adjustable strut/springs, front camber plates, better suspension bushings, bigger brakes for the front and rear, and wider Michelin Pilot Sport 2’s on Dinan’s signature 19-inch Alloy wheels.

The variety doesn’t stop with BMW. Dinan also designs and manufactures aftermarket performance parts for MINI that is supported by Dinan's 4 year/50,000 mile warranty to match the factory BMW and MINI warranty program.[1] Dinan’s MINI cooper S, Stage one, produces 225 bhp compared to the stock 180 hp. This bhp upgrade is done without increasing the stock boost pressure. The modifications that Dinan has changed on his “Stage one” MINI include Stage 3 engine software which allows the engine to breathe better, High Flow Cowl Induction Intake System, twin 3-inch diameter free flowing exhaust, and a strut tower brace.[3] In true Dinan fashion, the performance of the car cannot be increased without the addition of better delivery. Most tuners strive for the most rigid and stiff ride they can go for without the thought of the driver in mind.[1] Dinan has quality in mind, so he shot for a comfort ride at low and medium speeds without sacrificing the high-speed stability and handling. [3] [1 Kuah 65]

The Dinan badge is available at no cost to any vehicle owner who proves to the company that they have accumulated 10 points worth of performance upgrades to their vehicle. As of May 2012, the points were as follows: